JP2003243810A - Method of manufacturing printed wiring board equipped with very fine wire pattern - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high-density printed wiring board which is equipped with a very fine wire pattern excellent in adhesion to a copper foil and superior in shape. <P>SOLUTION: A layer made of nickel and/or cobalt or an alloy of them is deposited as thick as 0.1 to 5 μm on the rugged mat surface of an electrolytic copper foil, the electrolytic copper foil mounted with the above layer is used as the copper foil, the copper foil is deposited as an outermost layer on a copper plated board, the electrolytic copper foil as the outermost layer is selectively removed by etching, a thin electroless plating copper layer and an electrolytic copper layer are provided to the residual layer of nickel metal, cobalt metal or an alloy layer of them, a pattern plating resist layer is deposited thereon, a pattern electrolytic copper plating process is carried out, the plating resist layer is removed, then the thin electroless plating copper layer and the electrolytic copper layer are selectively removed by dissolution, and then the layer of nickel metal, cobalt or an alloy of them is selectively removed by etching for the formation of the high-density printed wiring board. Therefore, the high-density wiring board which is equipped with the very fine wire pattern nearly having no undercut and excellent in adhesion to the copper foil can be obtained. <P>COPYRIGHT: (C)2003,JPO

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the manufacture of a printed wiring board having a line / space pattern having an extremely fine line pattern, for example, a pattern of 40/40 .mu.m or less, and more preferably 25/25 .mu.m or less. The present invention relates to a method, and the high-density printed wiring board having the obtained ultrafine line pattern is mainly used for a new semiconductor plastic package or the like. 2. Description of the Related Art Conventionally, in a high-density printed wiring board used for a semiconductor plastic package or the like, a method of forming a fine line pattern is 5 μm by a subtractive method.
Using the following ultra-thin copper foil, after forming through-holes and / or blind via holes with a carbon dioxide laser or the like, depositing a plating resist and then depositing copper plating about 15 μm, removing the plating resist and removing the ultra-thin copper foil Either by etching or by irradiating a carbon dioxide gas laser directly on the copper foil to dissolve and remove the copper foil burrs generated in the holes after the formation of through-holes and / or blind via holes, and simultaneously remove the surface copper foil by SUEP (Surface Unifo
rm Etching Process), dissolving and removing from 12 μm thickness to 5 μm or less, and after desmearing, attaching a copper plating of about 15 μm and using a normal etching resist or the like to produce a pattern of ultrafine lines, etc. are known. . In this method, the pattern becomes thinner than the bottom by etching, and the cross section becomes trapezoidal or triangular, which has caused a defect. [0003] There is also a method of producing a fine line pattern using an etching resist after copper plating up by a semi-additive method. However, the same method is used when the copper plating thickness is increased to about 18 μm. When the thickness of the copper plating is reduced to about 10 μm, there is a defect that the adhesion thickness of the hole is insufficient and the reliability is poor. Furthermore, when copper plating adheres by the full additive method, there is a problem that the copper foil adhesion is low even if the copper foil is thickened. On the other hand, using an ultra-thin copper foil, electroless copper plating is applied on top of this by a few μm, then a pattern is formed by a pattern copper plating method, and furthermore, a few μm electroless copper layer is applied by a semi-additive method to the substrate. There is a method of forming a pattern by pattern copper plating using this, but the electroless copper layer is side-etched in the last flash etching, undercut occurs and there is a problem with copper adhesion It was something with SUMMARY OF THE INVENTION [0004] The present invention solves the above-mentioned problems by using a subtractive method. An object of the present invention is to provide a method for manufacturing a formed printed wiring board. SUMMARY OF THE INVENTION The present invention provides a high-density printed circuit having an extremely fine line pattern and excellent copper foil adhesion by manufacturing a printed wiring board in the following steps. A wiring board was obtained. That is, (1) nickel and / or
Or cobalt, or the surface layer of a double-sided copper-clad board or multilayer double-sided copper-clad board produced using an electrolytic copper foil having a thickness of 0.1 to 5 μm adhered to a surface having irregularities formed on one side of a copper foil as an outermost layer. The copper layer is removed by etching to leave nickel and / or cobalt or its alloy layer.
Applying an electroless copper plating of 0.1 to 1 μm, (3) forming an electrolytic copper plating layer having a thickness of 0.5 to 3 μm using the electroless copper plating deposited layer as an electrode, and (4) on the copper plating deposited layer Form a plating resist layer for pattern electroplating on necessary parts, (5)
On the copper surface where the plating resist layer is not formed, pattern copper plating is adhered by 6 to 30 μm by electrolytic copper plating, (6) the plating resist is peeled off, and (7) at least the portion where the pattern copper plating layer is not formed (8) Almost copper is dissolved after etching the entire surface of the thin electrolytic copper layer and electroless copper layer with a chemical solution that hardly dissolves nickel or cobalt or its alloy layer, leaving nickel or cobalt or its alloy layer. By etching the whole with a chemical solution that does not dissolve and remove the nickel or cobalt or its alloy layer to produce an ultrafine line pattern, a printed wiring board with ultrafine lines, good shape, and excellent adhesion is manufactured. I was able to. DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an electrolytic copper foil in which nickel and / or cobalt or an alloy thereof is adhered to a surface having irregularities on one side of a copper foil having a thickness of 0.1 to 5 μm as an outermost layer. The copper layer of the surface layer of the double-sided copper-clad board or multilayer double-sided copper-clad board produced by using nickel and / or cobalt,
Alternatively, there is a method of producing a high-density printed wiring board having a fine line pattern of line / space = 40/40 μm or less, and further 25/25 μm or less, by using the alloy layer left. The process is as follows: (1) First, nickel and / or cobalt or its alloy is applied to the outermost layer on the surface of the electrolytic copper foil with irregularities formed on one side.
A copper-clad board having at least two or more layers of copper foil is produced by using an electrolytic copper foil having 0.1 to 5 μm adhered as an outermost layer. Through holes and / or blind via holes are formed in the copper clad plate by a generally known method. Of course, holes may be formed after the electrolytic copper foil on the surface layer is removed by etching. The outermost layer is made of an electrolytic copper foil in which nickel and / or cobalt or an alloy thereof is adhered to a surface having irregularities formed on one side of the electrolytic copper foil with a thickness of 0.1 to 5 μm. A double-sided copper clad board or a multilayer double-sided copper clad board is produced by laminating under pressure, preferably under vacuum. The electrolytic copper foil on the surface of the double-sided copper-clad board or the multilayer double-sided copper-clad board is entirely removed by etching with a chemical solution that hardly dissolves nickel and / or cobalt or its alloy layer. Exposing the nickel and / or cobalt or its alloy layer. Thereafter, a through hole and / or a blind via hole is formed by a laser or a mechanical drill, or a through hole and / or a blind via hole is formed while leaving the electrolytic copper foil, and then only the electrolytic copper foil on the surface layer is etched away. A double-sided plate is prepared by leaving a nickel and / or cobalt or alloy layer of 0.1 to 5 μm on the surface layer by the method. (2) Next, electroless copper plating of 0.1 to 1 μm is applied to the surface of the double-sided board including the holes, including the inside of the holes. (3) Next, the electroless copper plating deposited layer was used as an electrode to a thickness of 0.5
An electrolytic copper plating layer of ~ 3 µm is formed. The type of copper plating is not particularly limited, and for example, copper sulfate plating, copper pyrophosphate plating, or the like can be used. (4) A plating resist layer for pattern copper electroplating is formed on required portions of the copper plating deposition layer. This step is also performed by a generally known method. (5) A pattern copper plating of 6 to 30 μm is adhered to the copper surface on which the plating resist layer is not formed by electrolytic copper plating. (6) The plating resist is peeled off. (7) At least the pattern copper plating layer After etching the entire thin copper layer and the electroless copper layer in the portion where no is formed with a chemical solution that hardly dissolves nickel or cobalt or its alloy layer, leaving nickel or cobalt or its alloy layer, 8) By etching the whole with a chemical solution that hardly dissolves copper and dissolving and removing nickel or cobalt or its alloy layer to produce an ultrafine line pattern, it is an ultrafine line, has a good shape, and has excellent adhesion. Manufacture printed wiring boards. By producing a fine pattern in this step, undercut does not occur as compared with the ordinary method,
A pattern having a good shape could be formed, and a printed wiring board excellent in reliability could be manufactured. As a chemical solution which selectively removes only copper and does not substantially dissolve nickel metal, cobalt metal, or an alloy thereof, a generally known chemical solution can be used, but an alkaline etching solution having a slow dissolution rate of nickel metal or the like is preferable. Used for Known chemicals can also be used as a chemical solution having a high etching rate for nickel metal, cobalt metal, or an alloy thereof and a low etching rate for copper.
For example, those mainly composed of sulfuric acid / hydrogen peroxide / additive, those mainly composed of ammonium fluoride / hydrogen peroxide / additive, and the like can be mentioned. As commercially available products, Pyutax (trade name of Mitsubishi Gas Chemical Co., Ltd.) and Melstrip N-950 (Meltex Co., Ltd.) are used. The copper-clad board used in the present invention is a copper-clad board having two or more copper layers. As the thermosetting resin copper-clad board, a known thermosetting resin of an inorganic or organic base material is used. Double-sided copper-clad laminates, the multilayer double-sided copper-clad laminates, multilayer boards made using a copper foil sheet with resin for the surface layer, etc., multilayer copper-clad boards of generally known configurations, also polyimide films, polyparabanic acid films, A copper-clad board of a substrate such as an aromatic polyamide film and a liquid crystal polyester film can be used. The substrate-reinforced copper-clad laminate is first impregnated with a thermosetting resin composition and dried to form a B stage,
Make a prepreg. Next, a predetermined number of the prepregs are stacked, and nickel and / or cobalt or an alloy thereof is formed on the outer surface of the copper foil with a thickness of 0.1 mm on one surface of the copper foil.
Electrodeposited copper foil having a thickness of about 5 μm is arranged on both sides, and laminated under heat, pressure, or preferably under vacuum to form a double-sided copper-clad laminate. The multilayer board is formed by processing a copper foil of a double-sided copper-clad laminate prepared using a known electrolytic copper foil on both sides to form a pattern, and if necessary, chemically treating the copper foil surface to produce an inner layer board, A prepreg, a B-stage resin sheet, etc. are placed on the outside, and an electrolytic copper foil having nickel and / or cobalt or an alloy thereof adhered to a surface having irregularities formed on one side of the copper foil with a thickness of 0.1 to 5 μm is arranged on both sides. Then, under heat, pressure, preferably laminated under the same vacuum, or nickel and / or cobalt, or an alloy thereof was attached to a surface having irregularities formed on one surface of the copper foil to a thickness of 0.1 to 5 μm. A generally known double-sided copper-clad multilayer board is produced by arranging a B-stage resin sheet adhered to the matte surface of an electrolytic copper foil on both sides of an inner layer board and laminating and forming a multilayer copper-clad board. As the substrate, generally known organic and inorganic woven fabrics and nonwoven fabrics can be used. Specific examples of the inorganic fibers include fibers such as E, S, D, and NE glass.
Examples of the organic fibers include generally known fibers such as wholly aromatic polyamide and liquid crystal polyester. These may be mixed. In addition, a film substrate is also used. As the resin of the thermosetting resin composition used in the present invention, generally known thermosetting resins are used.
Specifically, epoxy resin, polyfunctional cyanate resin, polyfunctional maleimide-cyanate resin,
Examples thereof include a polyfunctional maleimide resin and an unsaturated group-containing polyphenylene ether resin, and one kind or a combination of two or more kinds is used. From the viewpoint of through-hole shape in processing by high-output carbon dioxide laser irradiation, a thermosetting resin composition having a glass transition temperature of 150 ° C or higher is preferable,
A polyfunctional cyanate resin composition is preferred from the viewpoints of moisture resistance, migration resistance, electrical properties after moisture absorption, and the like. When the through-holes and / or blind via holes are formed by a carbon dioxide laser, the methods described in JP-A-11-220243 and JP-A-11-346059, and black copper oxide treatment, chemical treatment and the like are performed on the electrolytic copper foil. A method of directly irradiating a carbon dioxide laser on the copper foil from above the copper foil to form holes can be used. After that, the electrolytic copper foil on the surface layer is removed by etching, or the electrolytic copper foil is first removed by etching to expose the thin nickel metal, cobalt metal, or their alloyed layer, and then a carbon dioxide laser is applied directly from above. It is formed by a method of forming holes by irradiation. However, the latter is preferable from the viewpoint of the occurrence of burrs in the holes. Furthermore, UV-Y
Drilling is possible with an AG laser. In addition, through holes having a diameter of 100 μm or more are generally formed by a known method using a mechanical drill. As a method for forming a nickel metal, a cobalt metal, or an alloy thereof on the matte surface of the electrolytic copper foil, a generally known method can be used in the present invention. The size of the unevenness is not particularly limited, but preferably 1 to 3 μm is used from the viewpoint of producing a fine pattern. Conventionally known processing can be performed on the shiny surface of the copper foil. For example, there are used those having no surface irregularities and having this surface subjected to rust prevention treatment, those having a nickel metal, cobalt metal, or an alloy treatment layer thereof adhered to the surface layer of a shiny surface. The carbon dioxide laser is in the infrared wavelength range.
Wavelengths between 9.3 and 10.6 μm are commonly used. When drilling after removing the surface copper foil by etching, the energy is 5 to 3
The copper foil is processed by pulse oscillation at 0 mJ, preferably 6 to 20 mJ, and holes are made. Energy is radiated directly onto the surface layer of nickel metal, cobalt metal, or an alloy thereof to form holes. UV such as excimer laser and Nd-YAG laser
Laser hole formation can also be used. The UV laser is used for piercing by irradiating a laser beam having a UV wavelength. The wavelength is not particularly limited, but wavelengths of 200 to 400 nm and 1.06 μm are generally used. In particular, a solid state UV laser is used. In this method, the organic material is processed by a mechanism that cuts molecular bonds constituting the organic material without affecting the heat as much as possible. Since no carbon is generated in the holes as compared with the carbon dioxide laser and the holes are clean, the subsequent copper plating can be deposited with high reliability without any particular pretreatment. Because the UV laser wavelength is short, it is also absorbed by copper.By irradiating a laser on the copper foil without using a drilling auxiliary material, it is possible to drill holes in the copper foil and even drill the insulating layer. It is. After the entire surface is finally electroplated with copper, the plating resist for forming a pattern is peeled off and the entire nickel metal, cobalt metal, or an alloy-treated layer thereof is almost etched to form a thin copper layer. A pattern is formed by etching an electrolytic copper layer, a nickel metal, a cobalt metal, or an alloy-treated layer thereof until it reaches the substrate. The etchant is not particularly limited, and a generally known method such as a method using a ferric chloride, copper chloride, or ammonium persulfate solution can be used. In addition,
02-22887, 02-22896, 02-25089, 02-25090, 02
-59337, 02-60189, 02-166789, 03-25995, 03-
No. 60183, 03-94491, 04-199592, 04-263488, a method for dissolving and removing metal surfaces with chemicals (SUEP
Method). The etching rate is 0.02 to 1.0 μm / sec. The present invention will be specifically described below with reference to examples and comparative examples. Unless otherwise specified, “parts” indicates parts by weight. Example 1 900 parts of 2,2-bis (4-cyanatophenyl) propane,
100 parts of (maleimidophenyl) methane are melted at 150 ° C,
The mixture was reacted for 4 hours with stirring to obtain a prepolymer. This was dissolved in a mixed solvent of methyl ethyl ketone and dimethylformamide. Add bisphenol A type epoxy resin (trade name: Epicoat 1001, Yuka Shell Epoxy Co., Ltd.)
) And 600 parts of a cresol novolak type epoxy resin (trade name: ESCN-220F, manufactured by Sumitomo Chemical Co., Ltd.) were uniformly mixed and dissolved. Further, as a catalyst, zinc octylate 0.4
Was added and dissolved and mixed. To this, 2000 parts of an inorganic filler (trade name: calcined talc, manufactured by Nippon Talc Co., Ltd.) was added, and the mixture was uniformly stirred and mixed to obtain Varnish A. This varnish is impregnated with a glass woven fabric having a thickness of 100 μm, dried at 150 ° C., and subjected to a gelation time (at 170
C) 80 seconds, prepreg having a thermosetting resin composition content of 44% by weight (prepreg B), and impregnated into a glass woven fabric having a thickness of 50 μm, dried at 150 ° C, and gelled at 120 ° C. In seconds, a prepreg C having a thermosetting resin composition content of 70% by weight was prepared. A general electrolytic copper foil having a thickness of 18 μm is prepreg B 4
The ^two- sided copper-clad laminate D having an insulating layer thickness of 0.4 mm was obtained by arranging the upper and lower sheets and laminating them under vacuum at 200 ° C., 20 kgf / cm ² and 30 mmHg for 2 hours. After forming a pattern on this and subjecting it to black copper oxide treatment, one prepreg C is placed on each of the upper and lower sides, and a 12 μm-thick general electrolytic copper foil (mat surface unevenness Rz: 4.2 μm) is placed on the outside of the prepreg. A copper foil subjected to nickel treatment of 2.5 μm was placed on the surface layer and laminated and molded in the same manner to produce a four-layer double-sided copper-clad laminate E. The front and back 12 μm general electrolytic copper foils were removed by etching with an alkaline etching solution to obtain a four-layer double-sided metal-clad laminate F leaving only 2.5 μm of nickel treatment. On the other hand, polyvinyl alcohol powder is dissolved in water, and a resin layer having a thickness of 30 μm is formed on one side of a 50 μm thick aluminum.
μm, backup sheet G
Was prepared. A backup sheet G was placed under the four-layer double-sided metal foil-clad laminate F so that the resin surface faced the copper foil side, and was laminated with a roll at a temperature of 100 ° C. at a linear pressure of 15 kgf / cm. Good coating film was formed. At a distance of 1 mm, through-holes having a hole diameter of 100 μm were directly irradiated with 6 shots of a carbon dioxide laser at a pulse energy of 10 mJ to form through-holes. Also
A blind via hole having a hole diameter of 100 μm was formed by irradiating one shot of 12 mJ. After the desmear treatment, the copper foil is etched with a chemical that dissolves nickel (trade name: Pyutax, manufactured by Mitsubishi Gas Chemical Co., Ltd.) to dissolve the nickel foil to 2 μm,
Some burrs generated in the holes were dissolved and removed. To this, electroless copper plating was applied in a thickness of 0.4 μm, and then a copper layer having a thickness of 1 μm was applied by electrolytic copper plating. A resist layer for pattern copper electroplating was formed to a thickness of 18 μm on a required portion on the copper plating deposition layer, and a pattern copper plating of 15 μm was applied to the copper surface of the portion where the plating resist was not formed by copper electroplating. After stripping off all the plating resist, etching the entire surface with an alkaline etchant to remove the thin electrolytic copper layer and the electroless copper layer, and then removing only the nickel layer using the above chemical solution that dissolves nickel as a chemical solution. / Space = 25/25 μm pattern was formed. This pattern cross section had a good shape without undercut due to etching. A UV selective thermosetting permanent protection resist was adhered thereon, and nickel plating and gold plating were adhered to obtain a high-density printed wiring board. Table 1 shows the evaluation results of the printed wiring board. Example 2 Epoxy resin (trade name: Epicoat 5045) 700 parts, epoxy resin (trade name: ESCN220F) 300 parts, dicyandiamide 35
Part of 2-ethyl-4-methylimidazole was dissolved in a mixed solvent of methyl ethyl ketone and dimethylformamide, and 800 parts of the calcined talc of Example 1 was further added thereto. . This is impregnated into a glass woven fabric having a thickness of 100 μm, dried, and gelled for 150 seconds, a thermosetting resin composition content of 45% by weight of prepreg (prepreg I)
It was created. Use 6 prepreg I, 12μm thick
A copper foil with a nickel-cobalt alloy treatment applied to the surface layer of a general electrolytic copper foil (matte surface unevenness Rz: 2.7 μm) with a thickness of 3 μm is placed on both sides so that the alloy surface faces the prepreg side.
Laminate molding was performed for 2 hours under a vacuum of 20 ° C., 20 kgf / cm ² and 30 mmHg to produce a double-sided copper-clad laminate J. After removing the electrolytic copper foil portion by etching away the nickel-cobalt alloy treated layer of the copper foil of 3 μm on both surfaces, the backup sheet G of Example 1 was placed on the back surface, and the laminate was similarly laminated and bonded. The surface was irradiated with 8 shots of carbon dioxide laser pulse energy at 10 mJ to form a through hole having a hole diameter of 100 μm. Put this in a plasma device, after desmearing, apply a 0.3 μm thick electroless copper plating, then apply a 2 μm thick electrolytic copper plating, then attach a 15 μm plating resist for electrolytic copper plating Then, 14 μm of electrolytic copper plating was applied to the copper surface on which the plating resist layer was not formed. The plating resist was peeled off and the entire surface was flash-etched with an alkaline etching solution to dissolve and remove the thin electrolytic copper layer and the electroless copper layer up to the nickel-cobalt alloy layer. Further, the remaining nickel-cobalt alloy treated layer was dissolved and removed with the chemical solution for dissolving the nickel-based metal of Example 1 to produce a high-density printed wiring board having a line / space = 20/20 μm. After coating necessary portions with a UV-selective thermosetting permanent protection resist, nickel plating and gold plating were applied to form a printed wiring board. Table 1 shows the evaluation results. Comparative Example 1 In the production of the printed wiring board of Example 1, the thickness was
A general electrolytic copper foil of μm was applied, and this was etched to an average thickness of 3 μm to give a surface with irregularities of 1 μm. This is XY
Place on a table, irradiate 6 shots of 12 mJ carbon dioxide laser pulse energy from the surface to make a through hole with a hole diameter of 100 μm, and irradiate one shot of 12 mJ to form a blind via hole with a hole diameter of 100 μm, and copper plating after desmear treatment Was applied only by 3 μm of electroless copper plating, and a pattern electrolytic copper plating was applied directly on the electroless copper plating without applying the subsequent electrolytic copper plating. This was similarly etched to remove the thin electroless copper layer and the ultra-thin copper foil layer to which the pattern copper plating was not adhered, to obtain a printed wiring board. The underside of this pattern had an undercut of 5.4 μm on both sides. Table 1 shows the evaluation results. Comparative Example 2 A general electrolytic copper foil having a thickness of 12 μm was applied to the surface layer of the double-sided copper-clad laminate of Example 2, and this was etched to an average thickness of 3 μm to provide 1 μm irregularities on the surface. Place this on an XY table, irradiate 8 shots of 10 mJ carbon dioxide laser pulse energy from the surface to make through holes, similarly apply plasma treatment, apply 0.3 μm of electroless copper plating, and attach 14 μm of electrolytic copper plating Then, a 20 μm etching resist was attached thereon, and a pattern of line / space = 20/20 μm was formed by an ordinary method. However, the shape was triangular and the shape was not good. Table 1 shows the evaluation results. Comparative Example 3 After the surface copper foil and nickel metal layer of the double-sided copper-clad multilayer board of Example 1 were removed by etching, a through hole having a hole diameter of 100 μm was made with a carbon dioxide laser 15 mJ, and the surface was desmeared. Electroless copper plating was applied to 2 μm, and electrolytic copper plating was applied to 16 μm thereon. In the same manner as in Comparative Example 2, a pattern of line / space = 25/25 μm was formed. This had an undercut, the shape was triangular, and the shape was poor. Table 1 shows the evaluation results. Comparative Example 4 In Example 2, acrylonitrile butadiene rubber (trade name: N210S, JSR <
Co., Ltd.) was added, and the mixture was uniformly stirred and mixed. Thereafter, a prepreg was prepared in the same manner and laminated and molded to obtain a double-sided copper-clad laminate. After etching and removing the copper foil and nickel / cobalt layer on the surface layer of this copper clad board, the pore size was
A through hole of 100 μm is made, this surface is desmeared, electroless copper plating is applied to the entire surface by 4 μm, an electrolytic copper plating resist is attached, and an electrolytic copper plating is applied on the electroless copper plating where no plating resist is attached. Plating was deposited at 16 μm. After stripping the plating resist, the entire surface is etched to dissolve and remove the thin electroless copper plating layer, and line / space =
A 20/20 μm pattern was formed. This had an undercut. Table 1 shows the evaluation results. (Table 1) Item Example Comparative Example 1 2 1 2 3 4 Undercut (μm) <1 <1 5.5 <1 2.2 6.1 Pattern Cross Section Good Good Bad Triangular Triangular Bad Copper Adhesive Force (kgf / cm) 1.33 1.18 0.67 0.90 0.43 0.55 glass transition temperature (℃) 235 160 235 160 235 154 migration resistance (Omega) normal ^{5x10 14 6x10 14 5x10 14 4x10 14} 5x10 14 5x10 14 200hrs. 3x10 11 4x10 8 3x10 11 2x10 8 4x10 ^{11 2x10 8 500hrs. 6x10 10 <} 10 8 7x10 10 <10 8 5x10 10 <10 8 [0030] <measurement method> 1) the undercut and the pattern cross-sectional shape pattern section and 100 observed and expressed as mean values. The etched distance on one side is shown with respect to the design value. or,
The shape was also observed. 2) Copper foil adhesive strength was measured according to JIS C6481. The width was measured by the pattern width and converted to kgf / cm and displayed. 3) Glass transition temperature Measured according to the DMA method of JIS C6481. 4) Migration resistance In each of the examples and comparative examples, a thermosetting resist (trade name: BT-M450 manufactured by Mitsubishi Gas Chemical Co., Ltd.) was applied on the prepared pattern.
Is coated to a thickness of 40 μm, cured, and
5 ° C., 85% RH, 50 VDC was applied, and the insulation resistance between the patterns was measured. According to the method for producing an ultrafine wire pattern on a double-sided copper-clad board having at least two or more thin copper layers having through holes and / or blind via holes, an electrolytic copper foil is used as the copper foil. Use a copper foil with nickel metal, cobalt metal, or an alloy layer of 0.1 to 5 μm attached to the uneven surface of the mat surface, and attach it to at least the outermost layer. Only by selectively etching away, applying a thin electroless copper plating and an electrolytic copper plating on the remaining nickel metal, cobalt metal or their alloy layer, and then attaching a pattern plating resist to form a pattern electrolytic copper plating. After removing the plating resist, the whole is etched with a chemical solution with excellent solubility of copper and low solubility of nickel metal, cobalt metal or their alloy layers. Dissolve and remove the thin copper layer and the electroless copper layer to expose the nickel metal, cobalt metal or their alloy layer, and then the nickel metal, cobalt metal or their alloy layer has good solubility and copper By etching with a chemical solution having low solubility, a high-density printed wiring board with very little undercut, good shape, and excellent copper foil adhesion was produced.

[Brief description of the drawings] FIG. 1 is a diagram showing a thin line forming process of Example 1 (first half). FIG. 2 is a diagram showing a thin line forming process of Example 1 (second half). FIG. 3 is a diagram showing a thin line forming process of Comparative Example 1. FIG. 4 is a diagram showing a thin line forming process of Comparative Example 2. FIG. 5 is a diagram showing a thin line forming process of Comparative Example 3. FIG. 6 is a view showing a thin line forming process of Comparative Example 4. [Explanation of symbols] a laminated board b Nickel metal layer c Electroless copper plating layer d Electric copper plating layer e Hole formed f Plating resist g Electric copper pattern copper plating h Pattern etched copper layer i The remaining nickel metal layer j Patterns formed by etching all metal layers k Space part formed by etching metal layer l Generated pattern undercut m General electrolytic copper foil

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H05K 3/06 H05K 3/06 A 5E346 3/18 3/18 G J 3/46 3/46 S (72 ) Inventor Keiichi Iwata 6-1-1, Shinjuku, Katsushika-ku, Tokyo F-term in Tokyo Plant of Mitsubishi Gas Chemical Co., Ltd. 4E351 AA03 BB01 BB33 BB35 CC06 CC07 DD04 DD19 DD21 GG11 GG13 4K024 AA09 AB01 BA01 BB11 BC02 DA07 FA05 GA16 4K057 WA11 WB03 WC10 WE03 WE07 WE25 WN01 5E339 AB02 AD03 AD05 BC01 BD06 BD08 BE11 BE13 GG02 5E343 AA02 AA12 BB12 BB14 BB17 BB24 BB44 BB45 DD52 BB67 BB71 BB71 DD33 DD43 DD76 GG06 A08A12 A22 DD32 DD33 EE13 GG17 GG22 GG28 HH11 HH13 HH26 HH31

Claims (1)

Claims 1. (1) Nickel and / or cobalt or an alloy thereof is coated on a copper foil with a thickness of 0.1 on a surface having irregularities formed on one surface thereof.
~ 5μm electrolytic copper foil adhered to at least the outermost layer produced by using at least the outermost copper clad board or multilayer double-sided copper clad copper layer of the surface layer by etching and leaving nickel and / or cobalt, or its alloy layer, (2) electroless copper plating of 0.1 to 1 μm is applied to the surface including the inside of the hole, (3) an electrocopper plating layer having a thickness of 0.5 to 3 μm is formed by using the electroless copper plating deposited layer as an electrode,
(4) A plating resist layer for pattern electroplating is formed on a necessary portion on the copper plating deposition layer, and (5) a pattern copper plating is performed on the copper surface on which the plating resist layer is not formed by electrolytic copper plating. (6) Strip the plating resist and remove (7) At least the thin copper layer and electroless copper layer where the pattern copper plating layer is not formed are almost nickel or cobalt, or alloy layer thereof. Etch the entire surface with a chemical that does not dissolve, nickel or cobalt,
Alternatively, after leaving the alloy layer, (8) a print having an extra fine line pattern characterized by being manufactured by dissolving and removing nickel or cobalt or its alloy layer by etching the whole with a chemical solution that hardly dissolves copper. Manufacturing method of wiring board.